The Shag (BM) occurrence is located on the south side of Shag Creek, a northeast-flowing tributary of the Albert River. This is approximately 24 kilometres east of Radium Hot Springs and 9 kilometres west of the BC–Alberta border.
Regionally, the area is underlain by Middle Cambrian Cathedral Formation carbonates, laterally equivalent Chancellor Formation shales and limestones and Upper Cambrian McKay Group shales.
Locally, a number of small lead-zinc showings occur in a thick, massive to well-bedded limestone-dolostone unit of the Middle Cambrian Cathedral Formation and have been referred to as the BM, Redbed, Christmas, Pieces, Crackle, Rush and BM Extension occurrences. These occurrences extend between approximately 600 metres east and 3.3 kilometres northwest of the BM zone.
Most of the occurrences consist of galena and pale yellow to orange sphalerite in granular or brecciated dolostone, overlain by dark, laminated limestone. The sulphide concentrations appear to be restricted to two horizons, although a number of megascopically similar horizons occur in the succession. The dolostone at the ‘BM’ showing (the largest showing) consists of an erosional, basal surface overlain by massive or irregularly laminated dark dolomite capped by a coarse fragmental breccia or fenestral dolomite. This succession of cyclical beds is capped by dark, well-layered limestone.
Coarsely crystalline, yellow sphalerite and galena with traces of pyrite occur as blebs and/or disseminations within sparry dolomite or dark argillaceous limestone that is interstitial to breccia fragments, or as disseminated grains in more massive dolomite. Sphalerite and galena also occur within carbonate veinlets and shears.
In 1978, rock sample 703 assayed 48.4 per cent zinc, while another sample (702) assayed 28 per cent lead, 11.1 per cent zinc and 117.5 grams per tonne silver (Assessment Report 7036). In 1979, a drill hole (79-4) intercepted 2.8 metres yielding 3.77 grams per tonne silver and 1.22 per cent zinc (Assessment Report 8091). In 1981, a drill hole (81-2) in the Redbed zone intersected 1.3 metres yielding 14.6 per cent zinc and 30.35 grams per tonne silver (Assessment Report 10143). The following year, drill hole 82-2 intercepted 1.47 metres yielding 10.15 per cent zinc (Assessment Report 11170). In 1990, a rock sample (90-3) assayed 0.54 per cent zinc (Assessment Report 20538).
In 1977, Riocanex completed a regional program of geologic mapping, silt sampling and prospecting on the area as the Shag claims. In 1978, Rio Tinto Canadian Exploration Ltd. completed geological mapping, prospecting, diamond drilling and soil sampling on the claims. In 1979, Rio Tinto Canadian Exploration Ltd. conducted geological mapping, prospecting, soil sampling and six diamond drill holes totalling 460.6 metres. Work in 1981 by Esso Resources Canada Ltd. included geological mapping, geochemical sampling and diamond drilling and resulted in the discovery of a 600-metre length of weakly mineralized dolostone (Red Bed showing). In 1982, Esso Resources Canada Ltd. completed prospecting and diamond drilling. In 1988, Delta Geoscience Ltd. was contracted by Chris Graf of Ecstall Mining Corp. to conduct ground geophysical surveys. In 1990, Toklat Resources Inc. completed geochemical sampling and geophysical surveys. In 1991, Teck Corp. conducted soil sampling, geological mapping and limited prospecting. In 1998, Ecstall Mining Corp. completed a petrographic and chemical analysis of rock samples from the Shag claims.
